Heart assist jacket and method of using it

Abstract

A heart assist device for insertion into the thoracic cavity of a patient comprises a double-walled jacket (10) adapted to enclose at least the ventricular portion of the heart (H), at least the inner wall (11) of the jacket being pliable to be able to engage the outer surface of the heart and move together with the walls of the heart, and the interspace (13) between the inner and outer walls of the jacket being closed and filled with a fluid which is easily displaceable within the interspace.

I claim: 
     
       1. A passive heart assist device for insertion into the thoracic cavity of a patient between the thoracic wall and the heart comprising: a jacket having relatively moveable, connected inner and outer walls, wherein said inner wall is formed of pliable material and is adapted to fit snugly around at least the ventricular portion of the heart over the left and right ventricles; wherein said walls define a fluid-containing innerspace including a left ventricle portion and a right ventricle portion; wherein said portions are in fluid communication with one another; and means for maintaining a volume of fluid in said innerspace at all times, wherein said fluid is displaceable from one portion to the other in response to movement of one of the ventricles toward said outer wall thereby to enable the stroke volumes of the ventricles to vary as the heart beats.   
     
     
       2. A hear assist device as claimed in claim 1, wherein the inner wall of said jacket is adapted to fit snugly around substantially the entire heart and the jacket includes recesses defining openings for the veins and arteries leading to and from the heart, and further comprising means connecting portions of the jacket on opposite sides of the openings to each other. 
     
     
       3. A heart assist device as claimed in claim 2, wherein said jacket consists of a plurality of parts, each having relatively moveable, connected inner and outer walls and each part defining a part of said innerspace formed by its inner and outer walls, the inner walls of each jacket part consisting of pliable material and further comprising means joining the jacket parts to each other such that the parts in combination are adapted to fit snugly around substantially the entire heart and means for providing fluid communication between said parts of the jacket. 
     
     
       4. A heart assist device as claimed in claim 1, and further comprising an expansion reservoir and conduit means providing fluid communication between the jacket and the expansion reservoir. 
     
     
       5. A heart assist device as claimed in claim 1, wherein said fluid is a compressible fluid. 
     
     
       6. A heart assist device as claimed in claim 1, further comprising a conduit having one end in fluid communications with said jacket and having an opposite end covered by a self-sealing membrane through which fluid may be supplied to and removed from said jacket. 
     
     
       7. A method of supporting a patient's heart in vivo comprising the steps of: providing a jacket having relatively moveable, connected inner and outer walls, wherein said inner wall is formed of pliable material and is adapted to fit snugly around at least the ventricular portion of the heart over the left and right ventricles; wherein said walls define a fluid-containing innerspace including a left ventricle portion and a right ventricle portion; wherein said portions are in fluid communication with one another;   inserting said jacket into the thoracic cavity of a patient between the thoracic wall and the heart such that said left ventricle portion fits over said left ventricle and said right ventricle portions fit over said right ventricle; and   maintaining a volume of fluid in said innerspace at all times, wherein said fluid is displaced from one portion to the other in response to movement of one of the ventricles toward said outer wall with the jacket thus functioning passively to enable the stroke volumes of the ventricles to vary as the hear beats.   
     
     
       8. A method as claimed in claim 7 comprising the additional step of: adjusting the amount of fluid in said volume to control the degree of responsiveness of said inner wall to movement of said heart.